Advocates are warning immigrants to beware promises of permanent residency for a steep price.

One man says he saw someone giving away fliers on the street that asks for $1,500 in exchange for a visa. Another man says he received an e-mail telling him he won a visa lottery, but he would have to pay more than $900 to obtain the visa.

"You cannot buy a visa," said Father Brian Jordan, of the Franciscan Immigration Center. "You cannot buy a green card. You cannot buy your citizenship. It has to be earned."

Officials at the center say the U.S. Department of State awards about 50,000 visas annually to people coming from countries with low immigration rates.

There is no fee to fill out the lottery application, which is only available online, and winners are only notified via mail.

Related information:U.S. Department of State